Accidental events, reciprocal verbs, and the involuntary se
At B2, you need to go beyond the basic reflexives (levantarse, ducharse) to three advanced uses: reciprocal, accidental/involuntary, and pronominal verbs with changed meaning.
Reciprocal: Se escriben cada semana. (They write to each other every week.)
Involuntary: Se me olvidó el nombre. (I forgot the name — it slipped my mind.)
Changed meaning: ir → irse (to leave) · quedar → quedarse (to stay, to remain)
Plural reflexive pronouns (nos, os, se) can express that the action is mutual.
Se ayudan mutuamente. (They help each other.)
Nos conocimos en una conferencia. (We met each other at a conference.)
Siempre se discuten. — ambiguous; add el uno al otro / mutuamente to clarify.
Spanish has a special construction for accidents and unintended events: se + indirect object pronoun + verb + subject. The person is the indirect object, not the agent.
Se me olvidó el libro. (I forgot the book — literally: the book forgot itself to me.)
Se nos acabó la leche. (We ran out of milk.)
Se le cayó el móvil. (He/She dropped the phone.)
Key: the verb agrees with the thing (el libro → olvidó; la leche → acabó; el móvil → cayó).
Many important verbs have different meanings with and without the reflexive pronoun.
ir → irse: ir = to go · irse = to leave, to go away
quedar → quedarse: quedar = to arrange/to remain · quedarse = to stay
llevar → llevarse: llevar = to carry · llevarse bien con = to get on well with
perder → perderse: perder = to lose · perderse = to get lost / to miss out on
At B2, se also appears in formal passive and impersonal constructions — a key overlap to recognise.
Se habla español. (Spanish is spoken here.) — se pasivo
Se vive bien aquí. (Life is good here / One lives well here.) — impersonal
Se me cayeron los papeles. (I dropped my papers.) — involuntary
Traps for English speakers
These are the errors English speakers make most often.